​
Bayes' Theorem Calculator
Enter probabilities as decimals from 0 to 1
(Figures are recalculated when exiting any input field.)
P(​
H
1
​)
0.5
P(E|
H
1
​)
0.5
P(E|
H
2
​)
0.5
Priors
P(​
H
1
​)= 0.5
P(​
H
2
​)= 0.5
Likelihoods
P(E|
H
1
​)= 0.5
P(E|
H
2
​)= 0.5
Posteriors
P(​
H
1
|E)= 0.5
P(​
H
2
|E)= 0.5
Bayes' Theorem computes P(​
H
1
|E) from P(E|
H
1
​)​, P(E|
H
2
​)​, and P(​
H
1
​)​, where
(1) P(​
H
1
|E) is the probability of hypothesis
H
1
given evidence E
(2) P(E|
H
1
​) is the probability of evidence E given that hypothesis
H
1
is true
(3) P(E|
H
2
​) is the probability of evidence E given that hypothesis
H
2
is true
(4) P(​
H
1
​) is the probability of
H
1
apart from evidence E